1773 research outputs found
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Life and Death in the Chicxulub Impact Crater: A Record of the Paleocene–Eocene Thermal Maximum
Full text linkHere, we present a new record of the Paleocene–Eocene Thermal Maximum (PETM) from the peak ring of the Chicxulub impact crater that has been identified based on nannofossil biostratigraphy, an acme of the dinoflagellate genus Apectodinium, and a negative carbon isotope excursion.Vann Smith, Sophie Warny, Kliti Grice, Bettina Schaefer, Michael T. Whalen, Johan Vellekoop, Elise Chenot, Sean P. S. Gulick, Ignacio Arenillas, Jose A. Arz, Thorsten Bauersachs, Timothy Bralower, François Demory, Jérôme Gattacceca, Heather Jones, Johanna Lofi, Christopher M. Lowery, Joanna Morgan, Noelia B. Nuñez Otaño, Jennifer M. K. O'Keefe, Katherine O'Malley, Francisco J. Rodríguez-Tovar, Lorenz Schwark, and the IODP–ICDP Expedition 364 Scientist
Present-day volcanism on Venus as evidenced from weathering rates of olivine
No full textAt least some of Venus' lava flows are thought to be <2.5 million years old based on visible to near-infrared (VNIR) emissivity measured by the Venus Express spacecraft. However, the exact ages of these flows are poorly con-strained because the rate at which olivine alters at Venus surface conditions, and how that alteration affects VNIR spectra, remains unknown. We obtained VNIR reflectance spectra of natural olivine that was altered and oxidized in the laboratory. We show that olivine becomes coated, within days, with alteration products, primarily hematite (Fe2O3). With increasing alteration, the VNIR 1000-nm absorption, characteristic of olivine, also weakens within days. Our results indicate that lava flows lacking VNIR features due to hematite are no more than several years old. Therefore, Venus is volcanically active nowJustin Filiberto, David Trang, Allan H. Treiman and Martha S. Gilmor
Experimental Investigation of Oxidation of Pyroxene and Basalt: Implications for Spectroscopic Analyses of the Surface of Venus and the Ages of Lava Flows
No full textAlteration of basalt on the surface of Venus should be dominated by nanophase hematite and sulfate coatings, but the timescale of oxidation and how that affects spectroscopic measurements has not been extensively studied. The oxidation rate and the effect on reflectance spectroscopy are needed to constrain the age of lava flows with high emissivity that were previously measured by the European Space Agency's Venus Express Mission. Here we investigate the effects of oxidation on the mineralogy and visible to near-infrared (VNIR) spectroscopy of augite, diopside, pyroxenite, and an alkali basalt. The experimental and spectroscopic data are used to constrain the surface basaltic weathering rates for Venus. Further, we use the spectroscopic measurements to constrain how quickly igneous signatures would degrade during oxidation of the surface.K. S. Cutler, J. Filiberto, A. H. Treiman, and D. Tran
The importance of the study of igneous rocks and compositions to constrain the Martian planetary evolution.
No full textThis white paper summarizes the scientific importance of studying igneous compositions in meteorites, surface samples, and through orbital analyses to better constrain the geology of Mars as a whole and better understand the geological processes that have shaped Mars in the past and present.Arya Udry, Justin Filiberto, Juliane Gross, Mariek Schmidt, Deanne Rogers, Libby Hausrath, Roger Wiens, and Nina Lanz
Strategic Investment in Laboratory Analysis of Planetary Materials as Ground Truth for Solar System Exploration
No full textWe advocate for a robust allocation of resources needed to curate the existing samples, conduct targeted expansion of the collections, train the next generation of planetary materials analysts, and advance the state-of-the-art in sample analysis methods.Rhonda Stroud, Jessica Barnes, Larry Nittler, Juliane Gross, Jemma Davidson, Catherine Corrigan, Hope Ishii, Jamie Elsila Cook, Justin Filiberto, Samuel Lawrence, Michael Zolensky, Devin Schrader, Barbara Cohen, Kevin McKeegan, and CAPTE
Supplementary material for Volume 364 expedition reports
No full textSupplementary material for the Volume 364 expedition reports includes age-depth, MAR, and MAD data and fault-slip data in Microsoft Excel format; CT images and core line-scan images in JPG format; handwritten VCDs in PDF; and CT descriptions in a variety of native formats.J. Morgan, S. Gulick, C.L. Mellett, S.L. Green, and the Expedition 364 Scientist
Creating Inclusive, Supportive, and Safe Environments in Planetary Science for Members of the LGBTQ+ Community
No full textA White Paper in support of the 2023–2032 Planetary Science and Astrobiology Decadal Survey"I believe that no one should ever have to choose between a career we love and living our lives with authenticity and integrity." These words, spoken by Out and Equal Executive Director Selisse Berry, express the criticality of fostering an interdisciplinary, diverse, equitable, inclusive, and accessible environment over the next decade in the field of planetary science, especially for members of the LGBTQ+ community
Artemis 3 EVA Opportunities on the Rim of de Gerlache Crater
No full textSampling geologic materials, assessing potential ice deposits, and making the measurements described above will address science objectives 1a, 1e, 3a, 3b, 3d, 4a-d, 6d, 7b-c and potentially address 1a, 1b, 4e, and 7d [NRC (2007)], while also addressing strategic knowledge gaps (SKGs) I-D, I-G, II-D-3, III-C-2, III-D-1, III-D-2, III-D-4, and III-J-4 of the Scientific Context for Exploration of the Moon. National Academies Press, Washington D. C.D. A. Kring, J. M. Bretzelder, I. Ganesh, N. Kumari, A. Lang, and M. A. Siegle
How Artemis Can Accomplish Major Lunar Exploration Scientific Goals and Objectives: A Sampling Strategy and the "Artemis Rake"
No full textFor the Artemis-targeted unique lunar South-Circumpolar Region, we outline its Moon-wide context and major scientific problems and assess the optimal sampling strategy for initial and early Artemis human exploration missions to obtain a representative sample of the igneous (differentiation/petrogenesis) and metamorphic (impact-modified) history and cratering chronology of this unique lunar region.J. W. Head, H. H. Schmitt, D. R. Scott, C. M. Duke, L E. Borg, C. I. Fassett, B. L. Jolliff, C. R. Neal, C. M. Pieters, C. K. Sheare
Occator Crater, Ceres: XM2 High-resolution Mapping Products
No full textto be published in Nature Communications 2020. Consultation with author is recommended prior to use.Registered mosaics and DEMs for portions of floor of Occator crater, Ceres, from Dawn XM2 stereo image